1. Field of the Invention
The field of the invention relates to an improved cartridge, which is believed to be encompassed by art in Class 102/38 and indented sub-classes.
2. Description of the Prior Art
The hunting cartridges which are known heretofore include among their material constituents plastic. Plastics, in general, as they are well known, have a relatively low cost in comparison with other materials of construction and because they can be subjected to injection molding processes or manipulation, they are highly desirable material in the industry as a substitute for the classic materials.
As mentioned above, the use of plastics in the manufacture of cartridges is desirable but up to the present time even with the low construction cost of an element totally made in plastic without metallic reinforcement and with enough mechanical resistance to be utilized in its totality and able to be recharged, the use of plastics in the manufacture does not appear to have been accepted or widely practiced.
On the other hand, plastics have a disadvantage of requiring a cooling time in accordance with the thickness applied to the product that is formed by injection molding. In the injection molding process, particularly when the product thickness is considerable, the shrinkages are normally produced in the material in such a way that stress concentration appears in these shrinkages later on that may spoil the material. Therefore, it would be ideal to produce products having wall thickness reduced to the maximum permissible degree possible when employing plastics as a material of manufacture to eliminate shrinkage problems and also to reduce the required cooling time.
In the cartridge fabrication techniques, the use of a plastic cartridge case and the use of a single plastic piece which serves as a bottom and a base for the cartridge appear to be known in principle.
In the foregoing case, the thickness of the inner plastic piece invariably must be sufficiently dimensioned or thickened to theoretically provide the cartridge with adequate or corresponding mechanical strength. However, practice of the foregoing process resulted in an extraordinary slow fabrication process and a difference of resistance between the inner plastic piece and the case. Also in use of such parts made in plastic, separation of both zones occurred at times at the moment of powder-fumes expansion with the risks that it implies and making such use unadvisable. Consequently, these procedures never translated into practical use but remained only in theory. As a result, such use of plastic has not materialized heretofore due to the fabrication problems, forbidden cost and lack of adequate mechanical resistance.